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391.
介绍快速路西纵联络线立交跨河桥大跨径连续钢箱梁设计与施工方法,系统论述了设计过程,对关键节点详细分析,提出可行的设计方法,可为今后类似的桥梁建设提供经验。 相似文献
392.
利用层次分析法,分析了影响汽车制造商批量生产新能源汽车的关键因素,提出了不同层次的评估指标,建立了制造商对各类新能源汽车驱动技术的评估模型.对3种有望未来引进中国量产的国外新能源汽车进行动态评估,预测出未来20年其量产的趋势. 相似文献
393.
为了提高电压质量和电网运行安全系数,将一种10kV无功自动补偿装置应用在港口10kV配电所中。介绍了GWBZ-10无功自动补偿装置的配置、结构特点和应用效果。阐述了在港口配电所推广应用无功自动补偿装置的效果和现实意义。 相似文献
394.
为一台可变气门正时(VVT)发动机的配气相位调节器开发了一套可变气门正时机构的测试系统,完成了机油控制阀(OCV)工质流量特性的测试.分析了VVT动态响应特性的测试原理.借助该测试系统,测得不同的OCV、转速、温度和压力时相位器的动态响应曲线.最后进行了相位器泄漏量的测试. 相似文献
395.
396.
G. Xie S. D. Iwnicki 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2008,46(1):117-128
A new model for simulating rail roughness growth on tangent track is presented in this paper. The model consists of three relatively independent components: (1) a time-domain vehicle/track interaction model; (2) a 2D non-Hertzian and non-steady wheel/rail contact model; and (3) a wear model. Wheel/rail contact forces for a given initial roughness obtained from the vehicle/track interaction model are used by the contact model to calculate the contact patch size, normal pressure and tangential stresses with material removal assumed to be linearly proportional to the friction work in the contact patch. The roughness profile is updated and fed back into vehicle/track interaction model. The 2D contact model is initially compared with a 3D model for various wavelength of initial sinusoidal roughness. Long term roughness growth is then simulated with the 2D contact model. Simulation shows that all initial sinusoidal roughness of wavelengths between 20-100 mm are levelled out. The wavelength-fixing mechanism, that has previously been used to explain the cause of corrugation, is not found in the present investigations. 相似文献
397.
本文针对三面冲生产过程长期存在的偏孔问题分别从三面冲测量装置机械结构、测量装置调整方法以及一些特殊的原因等方面进行系统的分析,找到了导致三面冲偏孔的原因,并制定了相应的解决措施予以实施,成功的解决了三面冲偏孔这个质量问题。 相似文献
398.
In a connected vehicle environment, vehicles are able to communicate and exchange detailed information such as speed, acceleration, and position in real time. Such information exchange is important for improving traffic safety and mobility. This allows vehicles to collaborate with each other, which can significantly improve traffic operations particularly at intersections and freeway ramps. To assess the potential safety and mobility benefits of collaborative driving enabled by connected vehicle technologies, this study developed an optimization-based ramp control strategy and a simulation evaluation platform using VISSIM, MATLAB, and the Car2X module in VISSIM. The ramp control strategy is formulated as a constrained nonlinear optimization problem and solved by the MATLAB optimization toolbox. The optimization model provides individual vehicles with step-by-step control instructions in the ramp merging area. In addition to the optimization-based ramp control strategy, an empirical gradual speed limit control strategy is also formulated. These strategies are evaluated using the developed simulation platform in terms of average speed, average delay time, and throughput and are compared with a benchmark case with no control. The study results indicate that the proposed optimal control strategy can effectively coordinate merging vehicles at freeway on-ramps and substantially improve safety and mobility, especially when the freeway traffic is not oversaturated. The ramp control strategy can be further extended to improve traffic operations at bottlenecks caused by incidents, which cause approximately 25% of traffic congestion in the United States. 相似文献
399.
谢宝志 《现代城市轨道交通》2008,(3):30-31
南京站无站台柱雨棚下,利用特殊软横跨方案所实施的接触网悬挂工艺是国内的一项技术创新,通过进一步优化设计,其方案将具有借鉴、推广前景。 相似文献
400.